alanw
Well-known member
The ‘hobbits’ mysteriously disappeared 50,000 years ago. Our new study reveals what happened to their home
For a million years, one of humanity’s last cousins lived on an island in Indonesia. Why did they disappear?
theconversation.com
Onset of summer aridification and the decline of Homo floresiensis at Liang Bua 61,000 years ago - Communications Earth & Environment
Severe summer aridification caused freshwater scarcity and the decline of Homo floresiensis and its prey at Liang Bua 61,000 years ago, as revealed by a rainfall record based on speleothem geochemical data from the island of Flores, Indonesia.
www.nature.com
In optimal karst settings, speleothem Mg/Ca serves as an independent indicator of past changes in local monsoon rainfall. Accumulating evidence shows that prior calcite precipitation (PCP) in karst void spaces, where CO2 degassing occurs, can increase Mg/Ca in cave dripwaters due to preferential exclusion of Mg2+ during calcite formation. Reduced rainfall and karst infiltration rates create conditions favouring PCP, resulting in higher Mg/Ca in the speleothem ‘downstream’. In principle, tandem measurements of Mg/Ca and δ18O in speleothems can be used to infer rainfall seasonality.
